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v3.5.6
  1/*
  2 * NFS server file handle treatment.
  3 *
  4 * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
  5 * Portions Copyright (C) 1999 G. Allen Morris III <gam3@acm.org>
  6 * Extensive rewrite by Neil Brown <neilb@cse.unsw.edu.au> Southern-Spring 1999
  7 * ... and again Southern-Winter 2001 to support export_operations
  8 */
  9
 10#include <linux/exportfs.h>
 11
 12#include <linux/sunrpc/svcauth_gss.h>
 13#include "nfsd.h"
 14#include "vfs.h"
 15#include "auth.h"
 16
 17#define NFSDDBG_FACILITY		NFSDDBG_FH
 18
 19
 20/*
 21 * our acceptability function.
 22 * if NOSUBTREECHECK, accept anything
 23 * if not, require that we can walk up to exp->ex_dentry
 24 * doing some checks on the 'x' bits
 25 */
 26static int nfsd_acceptable(void *expv, struct dentry *dentry)
 27{
 28	struct svc_export *exp = expv;
 29	int rv;
 30	struct dentry *tdentry;
 31	struct dentry *parent;
 32
 33	if (exp->ex_flags & NFSEXP_NOSUBTREECHECK)
 34		return 1;
 35
 36	tdentry = dget(dentry);
 37	while (tdentry != exp->ex_path.dentry && !IS_ROOT(tdentry)) {
 38		/* make sure parents give x permission to user */
 39		int err;
 40		parent = dget_parent(tdentry);
 41		err = inode_permission(parent->d_inode, MAY_EXEC);
 42		if (err < 0) {
 43			dput(parent);
 44			break;
 45		}
 46		dput(tdentry);
 47		tdentry = parent;
 48	}
 49	if (tdentry != exp->ex_path.dentry)
 50		dprintk("nfsd_acceptable failed at %p %s\n", tdentry, tdentry->d_name.name);
 51	rv = (tdentry == exp->ex_path.dentry);
 52	dput(tdentry);
 53	return rv;
 54}
 55
 56/* Type check. The correct error return for type mismatches does not seem to be
 57 * generally agreed upon. SunOS seems to use EISDIR if file isn't S_IFREG; a
 58 * comment in the NFSv3 spec says this is incorrect (implementation notes for
 59 * the write call).
 60 */
 61static inline __be32
 62nfsd_mode_check(struct svc_rqst *rqstp, umode_t mode, umode_t requested)
 63{
 64	mode &= S_IFMT;
 65
 66	if (requested == 0) /* the caller doesn't care */
 67		return nfs_ok;
 68	if (mode == requested)
 69		return nfs_ok;
 70	/*
 71	 * v4 has an error more specific than err_notdir which we should
 72	 * return in preference to err_notdir:
 73	 */
 74	if (rqstp->rq_vers == 4 && mode == S_IFLNK)
 75		return nfserr_symlink;
 76	if (requested == S_IFDIR)
 77		return nfserr_notdir;
 78	if (mode == S_IFDIR)
 79		return nfserr_isdir;
 80	return nfserr_inval;
 
 
 
 81}
 82
 83static __be32 nfsd_setuser_and_check_port(struct svc_rqst *rqstp,
 84					  struct svc_export *exp)
 85{
 86	int flags = nfsexp_flags(rqstp, exp);
 87
 88	/* Check if the request originated from a secure port. */
 89	if (!rqstp->rq_secure && !(flags & NFSEXP_INSECURE_PORT)) {
 90		RPC_IFDEBUG(char buf[RPC_MAX_ADDRBUFLEN]);
 91		dprintk(KERN_WARNING
 92		       "nfsd: request from insecure port %s!\n",
 93		       svc_print_addr(rqstp, buf, sizeof(buf)));
 94		return nfserr_perm;
 95	}
 96
 97	/* Set user creds for this exportpoint */
 98	return nfserrno(nfsd_setuser(rqstp, exp));
 99}
100
101static inline __be32 check_pseudo_root(struct svc_rqst *rqstp,
102	struct dentry *dentry, struct svc_export *exp)
103{
104	if (!(exp->ex_flags & NFSEXP_V4ROOT))
105		return nfs_ok;
106	/*
107	 * v2/v3 clients have no need for the V4ROOT export--they use
108	 * the mount protocl instead; also, further V4ROOT checks may be
109	 * in v4-specific code, in which case v2/v3 clients could bypass
110	 * them.
111	 */
112	if (!nfsd_v4client(rqstp))
113		return nfserr_stale;
114	/*
115	 * We're exposing only the directories and symlinks that have to be
116	 * traversed on the way to real exports:
117	 */
118	if (unlikely(!S_ISDIR(dentry->d_inode->i_mode) &&
119		     !S_ISLNK(dentry->d_inode->i_mode)))
120		return nfserr_stale;
121	/*
122	 * A pseudoroot export gives permission to access only one
123	 * single directory; the kernel has to make another upcall
124	 * before granting access to anything else under it:
125	 */
126	if (unlikely(dentry != exp->ex_path.dentry))
127		return nfserr_stale;
128	return nfs_ok;
129}
130
131/*
132 * Use the given filehandle to look up the corresponding export and
133 * dentry.  On success, the results are used to set fh_export and
134 * fh_dentry.
135 */
136static __be32 nfsd_set_fh_dentry(struct svc_rqst *rqstp, struct svc_fh *fhp)
137{
138	struct knfsd_fh	*fh = &fhp->fh_handle;
139	struct fid *fid = NULL, sfid;
140	struct svc_export *exp;
141	struct dentry *dentry;
142	int fileid_type;
143	int data_left = fh->fh_size/4;
144	__be32 error;
145
146	error = nfserr_stale;
147	if (rqstp->rq_vers > 2)
148		error = nfserr_badhandle;
149	if (rqstp->rq_vers == 4 && fh->fh_size == 0)
150		return nfserr_nofilehandle;
151
152	if (fh->fh_version == 1) {
153		int len;
154
155		if (--data_left < 0)
156			return error;
157		if (fh->fh_auth_type != 0)
158			return error;
159		len = key_len(fh->fh_fsid_type) / 4;
160		if (len == 0)
161			return error;
162		if  (fh->fh_fsid_type == FSID_MAJOR_MINOR) {
163			/* deprecated, convert to type 3 */
164			len = key_len(FSID_ENCODE_DEV)/4;
165			fh->fh_fsid_type = FSID_ENCODE_DEV;
166			fh->fh_fsid[0] = new_encode_dev(MKDEV(ntohl(fh->fh_fsid[0]), ntohl(fh->fh_fsid[1])));
167			fh->fh_fsid[1] = fh->fh_fsid[2];
168		}
169		data_left -= len;
170		if (data_left < 0)
171			return error;
172		exp = rqst_exp_find(rqstp, fh->fh_fsid_type, fh->fh_auth);
173		fid = (struct fid *)(fh->fh_auth + len);
174	} else {
175		__u32 tfh[2];
176		dev_t xdev;
177		ino_t xino;
178
179		if (fh->fh_size != NFS_FHSIZE)
180			return error;
181		/* assume old filehandle format */
182		xdev = old_decode_dev(fh->ofh_xdev);
183		xino = u32_to_ino_t(fh->ofh_xino);
184		mk_fsid(FSID_DEV, tfh, xdev, xino, 0, NULL);
185		exp = rqst_exp_find(rqstp, FSID_DEV, tfh);
186	}
187
188	error = nfserr_stale;
189	if (PTR_ERR(exp) == -ENOENT)
190		return error;
191
192	if (IS_ERR(exp))
193		return nfserrno(PTR_ERR(exp));
194
195	if (exp->ex_flags & NFSEXP_NOSUBTREECHECK) {
196		/* Elevate privileges so that the lack of 'r' or 'x'
197		 * permission on some parent directory will
198		 * not stop exportfs_decode_fh from being able
199		 * to reconnect a directory into the dentry cache.
200		 * The same problem can affect "SUBTREECHECK" exports,
201		 * but as nfsd_acceptable depends on correct
202		 * access control settings being in effect, we cannot
203		 * fix that case easily.
204		 */
205		struct cred *new = prepare_creds();
206		if (!new)
207			return nfserrno(-ENOMEM);
208		new->cap_effective =
209			cap_raise_nfsd_set(new->cap_effective,
210					   new->cap_permitted);
211		put_cred(override_creds(new));
212		put_cred(new);
213	} else {
214		error = nfsd_setuser_and_check_port(rqstp, exp);
215		if (error)
216			goto out;
217	}
218
219	/*
220	 * Look up the dentry using the NFS file handle.
221	 */
222	error = nfserr_stale;
223	if (rqstp->rq_vers > 2)
224		error = nfserr_badhandle;
225
226	if (fh->fh_version != 1) {
227		sfid.i32.ino = fh->ofh_ino;
228		sfid.i32.gen = fh->ofh_generation;
229		sfid.i32.parent_ino = fh->ofh_dirino;
230		fid = &sfid;
231		data_left = 3;
232		if (fh->ofh_dirino == 0)
233			fileid_type = FILEID_INO32_GEN;
234		else
235			fileid_type = FILEID_INO32_GEN_PARENT;
236	} else
237		fileid_type = fh->fh_fileid_type;
238
239	if (fileid_type == FILEID_ROOT)
240		dentry = dget(exp->ex_path.dentry);
241	else {
242		dentry = exportfs_decode_fh(exp->ex_path.mnt, fid,
243				data_left, fileid_type,
244				nfsd_acceptable, exp);
245	}
246	if (dentry == NULL)
247		goto out;
248	if (IS_ERR(dentry)) {
249		if (PTR_ERR(dentry) != -EINVAL)
250			error = nfserrno(PTR_ERR(dentry));
251		goto out;
252	}
253
254	if (S_ISDIR(dentry->d_inode->i_mode) &&
255			(dentry->d_flags & DCACHE_DISCONNECTED)) {
256		printk("nfsd: find_fh_dentry returned a DISCONNECTED directory: %s/%s\n",
257				dentry->d_parent->d_name.name, dentry->d_name.name);
258	}
259
260	fhp->fh_dentry = dentry;
261	fhp->fh_export = exp;
262	return 0;
263out:
264	exp_put(exp);
265	return error;
266}
267
268/**
269 * fh_verify - filehandle lookup and access checking
270 * @rqstp: pointer to current rpc request
271 * @fhp: filehandle to be verified
272 * @type: expected type of object pointed to by filehandle
273 * @access: type of access needed to object
274 *
275 * Look up a dentry from the on-the-wire filehandle, check the client's
276 * access to the export, and set the current task's credentials.
277 *
278 * Regardless of success or failure of fh_verify(), fh_put() should be
279 * called on @fhp when the caller is finished with the filehandle.
280 *
281 * fh_verify() may be called multiple times on a given filehandle, for
282 * example, when processing an NFSv4 compound.  The first call will look
283 * up a dentry using the on-the-wire filehandle.  Subsequent calls will
284 * skip the lookup and just perform the other checks and possibly change
285 * the current task's credentials.
286 *
287 * @type specifies the type of object expected using one of the S_IF*
288 * constants defined in include/linux/stat.h.  The caller may use zero
289 * to indicate that it doesn't care, or a negative integer to indicate
290 * that it expects something not of the given type.
291 *
292 * @access is formed from the NFSD_MAY_* constants defined in
293 * include/linux/nfsd/nfsd.h.
294 */
295__be32
296fh_verify(struct svc_rqst *rqstp, struct svc_fh *fhp, umode_t type, int access)
297{
298	struct svc_export *exp;
299	struct dentry	*dentry;
300	__be32		error;
301
302	dprintk("nfsd: fh_verify(%s)\n", SVCFH_fmt(fhp));
303
304	if (!fhp->fh_dentry) {
305		error = nfsd_set_fh_dentry(rqstp, fhp);
306		if (error)
307			goto out;
308	}
309	dentry = fhp->fh_dentry;
310	exp = fhp->fh_export;
311	/*
312	 * We still have to do all these permission checks, even when
313	 * fh_dentry is already set:
314	 * 	- fh_verify may be called multiple times with different
315	 * 	  "access" arguments (e.g. nfsd_proc_create calls
316	 * 	  fh_verify(...,NFSD_MAY_EXEC) first, then later (in
317	 * 	  nfsd_create) calls fh_verify(...,NFSD_MAY_CREATE).
318	 *	- in the NFSv4 case, the filehandle may have been filled
319	 *	  in by fh_compose, and given a dentry, but further
320	 *	  compound operations performed with that filehandle
321	 *	  still need permissions checks.  In the worst case, a
322	 *	  mountpoint crossing may have changed the export
323	 *	  options, and we may now need to use a different uid
324	 *	  (for example, if different id-squashing options are in
325	 *	  effect on the new filesystem).
326	 */
327	error = check_pseudo_root(rqstp, dentry, exp);
328	if (error)
329		goto out;
330
331	error = nfsd_setuser_and_check_port(rqstp, exp);
332	if (error)
333		goto out;
334
335	error = nfsd_mode_check(rqstp, dentry->d_inode->i_mode, type);
336	if (error)
337		goto out;
338
339	/*
340	 * pseudoflavor restrictions are not enforced on NLM,
341	 * which clients virtually always use auth_sys for,
342	 * even while using RPCSEC_GSS for NFS.
343	 */
344	if (access & NFSD_MAY_LOCK || access & NFSD_MAY_BYPASS_GSS)
345		goto skip_pseudoflavor_check;
346	/*
347	 * Clients may expect to be able to use auth_sys during mount,
348	 * even if they use gss for everything else; see section 2.3.2
349	 * of rfc 2623.
350	 */
351	if (access & NFSD_MAY_BYPASS_GSS_ON_ROOT
352			&& exp->ex_path.dentry == dentry)
353		goto skip_pseudoflavor_check;
354
355	error = check_nfsd_access(exp, rqstp);
356	if (error)
357		goto out;
358
359skip_pseudoflavor_check:
360	/* Finally, check access permissions. */
361	error = nfsd_permission(rqstp, exp, dentry, access);
362
363	if (error) {
364		dprintk("fh_verify: %s/%s permission failure, "
365			"acc=%x, error=%d\n",
366			dentry->d_parent->d_name.name,
367			dentry->d_name.name,
368			access, ntohl(error));
369	}
370out:
371	if (error == nfserr_stale)
372		nfsdstats.fh_stale++;
373	return error;
374}
375
376
377/*
378 * Compose a file handle for an NFS reply.
379 *
380 * Note that when first composed, the dentry may not yet have
381 * an inode.  In this case a call to fh_update should be made
382 * before the fh goes out on the wire ...
383 */
384static void _fh_update(struct svc_fh *fhp, struct svc_export *exp,
385		struct dentry *dentry)
386{
387	if (dentry != exp->ex_path.dentry) {
388		struct fid *fid = (struct fid *)
389			(fhp->fh_handle.fh_auth + fhp->fh_handle.fh_size/4 - 1);
390		int maxsize = (fhp->fh_maxsize - fhp->fh_handle.fh_size)/4;
391		int subtreecheck = !(exp->ex_flags & NFSEXP_NOSUBTREECHECK);
392
393		fhp->fh_handle.fh_fileid_type =
394			exportfs_encode_fh(dentry, fid, &maxsize, subtreecheck);
395		fhp->fh_handle.fh_size += maxsize * 4;
396	} else {
397		fhp->fh_handle.fh_fileid_type = FILEID_ROOT;
398	}
399}
400
401/*
402 * for composing old style file handles
403 */
404static inline void _fh_update_old(struct dentry *dentry,
405				  struct svc_export *exp,
406				  struct knfsd_fh *fh)
407{
408	fh->ofh_ino = ino_t_to_u32(dentry->d_inode->i_ino);
409	fh->ofh_generation = dentry->d_inode->i_generation;
410	if (S_ISDIR(dentry->d_inode->i_mode) ||
411	    (exp->ex_flags & NFSEXP_NOSUBTREECHECK))
412		fh->ofh_dirino = 0;
413}
414
415static bool is_root_export(struct svc_export *exp)
416{
417	return exp->ex_path.dentry == exp->ex_path.dentry->d_sb->s_root;
418}
419
420static struct super_block *exp_sb(struct svc_export *exp)
421{
422	return exp->ex_path.dentry->d_inode->i_sb;
423}
424
425static bool fsid_type_ok_for_exp(u8 fsid_type, struct svc_export *exp)
426{
427	switch (fsid_type) {
428	case FSID_DEV:
429		if (!old_valid_dev(exp_sb(exp)->s_dev))
430			return 0;
431		/* FALL THROUGH */
432	case FSID_MAJOR_MINOR:
433	case FSID_ENCODE_DEV:
434		return exp_sb(exp)->s_type->fs_flags & FS_REQUIRES_DEV;
435	case FSID_NUM:
436		return exp->ex_flags & NFSEXP_FSID;
437	case FSID_UUID8:
438	case FSID_UUID16:
439		if (!is_root_export(exp))
440			return 0;
441		/* fall through */
442	case FSID_UUID4_INUM:
443	case FSID_UUID16_INUM:
444		return exp->ex_uuid != NULL;
445	}
446	return 1;
447}
448
449
450static void set_version_and_fsid_type(struct svc_fh *fhp, struct svc_export *exp, struct svc_fh *ref_fh)
451{
452	u8 version;
453	u8 fsid_type;
454retry:
455	version = 1;
456	if (ref_fh && ref_fh->fh_export == exp) {
457		version = ref_fh->fh_handle.fh_version;
458		fsid_type = ref_fh->fh_handle.fh_fsid_type;
459
460		ref_fh = NULL;
461
462		switch (version) {
463		case 0xca:
464			fsid_type = FSID_DEV;
465			break;
466		case 1:
467			break;
468		default:
469			goto retry;
470		}
471
472		/*
473		 * As the fsid -> filesystem mapping was guided by
474		 * user-space, there is no guarantee that the filesystem
475		 * actually supports that fsid type. If it doesn't we
476		 * loop around again without ref_fh set.
477		 */
478		if (!fsid_type_ok_for_exp(fsid_type, exp))
479			goto retry;
480	} else if (exp->ex_flags & NFSEXP_FSID) {
481		fsid_type = FSID_NUM;
482	} else if (exp->ex_uuid) {
483		if (fhp->fh_maxsize >= 64) {
484			if (is_root_export(exp))
485				fsid_type = FSID_UUID16;
486			else
487				fsid_type = FSID_UUID16_INUM;
488		} else {
489			if (is_root_export(exp))
490				fsid_type = FSID_UUID8;
491			else
492				fsid_type = FSID_UUID4_INUM;
493		}
494	} else if (!old_valid_dev(exp_sb(exp)->s_dev))
495		/* for newer device numbers, we must use a newer fsid format */
496		fsid_type = FSID_ENCODE_DEV;
497	else
498		fsid_type = FSID_DEV;
499	fhp->fh_handle.fh_version = version;
500	if (version)
501		fhp->fh_handle.fh_fsid_type = fsid_type;
502}
503
504__be32
505fh_compose(struct svc_fh *fhp, struct svc_export *exp, struct dentry *dentry,
506	   struct svc_fh *ref_fh)
507{
508	/* ref_fh is a reference file handle.
509	 * if it is non-null and for the same filesystem, then we should compose
510	 * a filehandle which is of the same version, where possible.
511	 * Currently, that means that if ref_fh->fh_handle.fh_version == 0xca
512	 * Then create a 32byte filehandle using nfs_fhbase_old
513	 *
514	 */
515
516	struct inode * inode = dentry->d_inode;
517	struct dentry *parent = dentry->d_parent;
518	__u32 *datap;
519	dev_t ex_dev = exp_sb(exp)->s_dev;
520
521	dprintk("nfsd: fh_compose(exp %02x:%02x/%ld %s/%s, ino=%ld)\n",
522		MAJOR(ex_dev), MINOR(ex_dev),
523		(long) exp->ex_path.dentry->d_inode->i_ino,
524		parent->d_name.name, dentry->d_name.name,
525		(inode ? inode->i_ino : 0));
526
527	/* Choose filehandle version and fsid type based on
528	 * the reference filehandle (if it is in the same export)
529	 * or the export options.
530	 */
531	 set_version_and_fsid_type(fhp, exp, ref_fh);
532
533	if (ref_fh == fhp)
534		fh_put(ref_fh);
535
536	if (fhp->fh_locked || fhp->fh_dentry) {
537		printk(KERN_ERR "fh_compose: fh %s/%s not initialized!\n",
538		       parent->d_name.name, dentry->d_name.name);
539	}
540	if (fhp->fh_maxsize < NFS_FHSIZE)
541		printk(KERN_ERR "fh_compose: called with maxsize %d! %s/%s\n",
542		       fhp->fh_maxsize,
543		       parent->d_name.name, dentry->d_name.name);
544
545	fhp->fh_dentry = dget(dentry); /* our internal copy */
546	fhp->fh_export = exp;
547	cache_get(&exp->h);
548
549	if (fhp->fh_handle.fh_version == 0xca) {
550		/* old style filehandle please */
551		memset(&fhp->fh_handle.fh_base, 0, NFS_FHSIZE);
552		fhp->fh_handle.fh_size = NFS_FHSIZE;
553		fhp->fh_handle.ofh_dcookie = 0xfeebbaca;
554		fhp->fh_handle.ofh_dev =  old_encode_dev(ex_dev);
555		fhp->fh_handle.ofh_xdev = fhp->fh_handle.ofh_dev;
556		fhp->fh_handle.ofh_xino =
557			ino_t_to_u32(exp->ex_path.dentry->d_inode->i_ino);
558		fhp->fh_handle.ofh_dirino = ino_t_to_u32(parent_ino(dentry));
559		if (inode)
560			_fh_update_old(dentry, exp, &fhp->fh_handle);
561	} else {
562		int len;
563		fhp->fh_handle.fh_auth_type = 0;
564		datap = fhp->fh_handle.fh_auth+0;
565		mk_fsid(fhp->fh_handle.fh_fsid_type, datap, ex_dev,
566			exp->ex_path.dentry->d_inode->i_ino,
567			exp->ex_fsid, exp->ex_uuid);
568
569		len = key_len(fhp->fh_handle.fh_fsid_type);
570		datap += len/4;
571		fhp->fh_handle.fh_size = 4 + len;
572
573		if (inode)
574			_fh_update(fhp, exp, dentry);
575		if (fhp->fh_handle.fh_fileid_type == 255) {
576			fh_put(fhp);
577			return nfserr_opnotsupp;
578		}
579	}
580
581	return 0;
582}
583
584/*
585 * Update file handle information after changing a dentry.
586 * This is only called by nfsd_create, nfsd_create_v3 and nfsd_proc_create
587 */
588__be32
589fh_update(struct svc_fh *fhp)
590{
591	struct dentry *dentry;
592
593	if (!fhp->fh_dentry)
594		goto out_bad;
595
596	dentry = fhp->fh_dentry;
597	if (!dentry->d_inode)
598		goto out_negative;
599	if (fhp->fh_handle.fh_version != 1) {
600		_fh_update_old(dentry, fhp->fh_export, &fhp->fh_handle);
601	} else {
602		if (fhp->fh_handle.fh_fileid_type != FILEID_ROOT)
603			goto out;
604
605		_fh_update(fhp, fhp->fh_export, dentry);
606		if (fhp->fh_handle.fh_fileid_type == 255)
607			return nfserr_opnotsupp;
608	}
609out:
610	return 0;
611
612out_bad:
613	printk(KERN_ERR "fh_update: fh not verified!\n");
614	goto out;
615out_negative:
616	printk(KERN_ERR "fh_update: %s/%s still negative!\n",
617		dentry->d_parent->d_name.name, dentry->d_name.name);
618	goto out;
619}
620
621/*
622 * Release a file handle.
623 */
624void
625fh_put(struct svc_fh *fhp)
626{
627	struct dentry * dentry = fhp->fh_dentry;
628	struct svc_export * exp = fhp->fh_export;
629	if (dentry) {
630		fh_unlock(fhp);
631		fhp->fh_dentry = NULL;
632		dput(dentry);
633#ifdef CONFIG_NFSD_V3
634		fhp->fh_pre_saved = 0;
635		fhp->fh_post_saved = 0;
636#endif
637	}
638	if (exp) {
639		exp_put(exp);
640		fhp->fh_export = NULL;
641	}
642	return;
643}
644
645/*
646 * Shorthand for dprintk()'s
647 */
648char * SVCFH_fmt(struct svc_fh *fhp)
649{
650	struct knfsd_fh *fh = &fhp->fh_handle;
651
652	static char buf[80];
653	sprintf(buf, "%d: %08x %08x %08x %08x %08x %08x",
654		fh->fh_size,
655		fh->fh_base.fh_pad[0],
656		fh->fh_base.fh_pad[1],
657		fh->fh_base.fh_pad[2],
658		fh->fh_base.fh_pad[3],
659		fh->fh_base.fh_pad[4],
660		fh->fh_base.fh_pad[5]);
661	return buf;
662}
663
664enum fsid_source fsid_source(struct svc_fh *fhp)
665{
666	if (fhp->fh_handle.fh_version != 1)
667		return FSIDSOURCE_DEV;
668	switch(fhp->fh_handle.fh_fsid_type) {
669	case FSID_DEV:
670	case FSID_ENCODE_DEV:
671	case FSID_MAJOR_MINOR:
672		if (exp_sb(fhp->fh_export)->s_type->fs_flags & FS_REQUIRES_DEV)
673			return FSIDSOURCE_DEV;
674		break;
675	case FSID_NUM:
676		if (fhp->fh_export->ex_flags & NFSEXP_FSID)
677			return FSIDSOURCE_FSID;
678		break;
679	default:
680		break;
681	}
682	/* either a UUID type filehandle, or the filehandle doesn't
683	 * match the export.
684	 */
685	if (fhp->fh_export->ex_flags & NFSEXP_FSID)
686		return FSIDSOURCE_FSID;
687	if (fhp->fh_export->ex_uuid)
688		return FSIDSOURCE_UUID;
689	return FSIDSOURCE_DEV;
690}
v3.1
  1/*
  2 * NFS server file handle treatment.
  3 *
  4 * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
  5 * Portions Copyright (C) 1999 G. Allen Morris III <gam3@acm.org>
  6 * Extensive rewrite by Neil Brown <neilb@cse.unsw.edu.au> Southern-Spring 1999
  7 * ... and again Southern-Winter 2001 to support export_operations
  8 */
  9
 10#include <linux/exportfs.h>
 11
 12#include <linux/sunrpc/svcauth_gss.h>
 13#include "nfsd.h"
 14#include "vfs.h"
 15#include "auth.h"
 16
 17#define NFSDDBG_FACILITY		NFSDDBG_FH
 18
 19
 20/*
 21 * our acceptability function.
 22 * if NOSUBTREECHECK, accept anything
 23 * if not, require that we can walk up to exp->ex_dentry
 24 * doing some checks on the 'x' bits
 25 */
 26static int nfsd_acceptable(void *expv, struct dentry *dentry)
 27{
 28	struct svc_export *exp = expv;
 29	int rv;
 30	struct dentry *tdentry;
 31	struct dentry *parent;
 32
 33	if (exp->ex_flags & NFSEXP_NOSUBTREECHECK)
 34		return 1;
 35
 36	tdentry = dget(dentry);
 37	while (tdentry != exp->ex_path.dentry && !IS_ROOT(tdentry)) {
 38		/* make sure parents give x permission to user */
 39		int err;
 40		parent = dget_parent(tdentry);
 41		err = inode_permission(parent->d_inode, MAY_EXEC);
 42		if (err < 0) {
 43			dput(parent);
 44			break;
 45		}
 46		dput(tdentry);
 47		tdentry = parent;
 48	}
 49	if (tdentry != exp->ex_path.dentry)
 50		dprintk("nfsd_acceptable failed at %p %s\n", tdentry, tdentry->d_name.name);
 51	rv = (tdentry == exp->ex_path.dentry);
 52	dput(tdentry);
 53	return rv;
 54}
 55
 56/* Type check. The correct error return for type mismatches does not seem to be
 57 * generally agreed upon. SunOS seems to use EISDIR if file isn't S_IFREG; a
 58 * comment in the NFSv3 spec says this is incorrect (implementation notes for
 59 * the write call).
 60 */
 61static inline __be32
 62nfsd_mode_check(struct svc_rqst *rqstp, umode_t mode, int type)
 63{
 64	/* Type can be negative when creating hardlinks - not to a dir */
 65	if (type > 0 && (mode & S_IFMT) != type) {
 66		if (rqstp->rq_vers == 4 && (mode & S_IFMT) == S_IFLNK)
 67			return nfserr_symlink;
 68		else if (type == S_IFDIR)
 69			return nfserr_notdir;
 70		else if ((mode & S_IFMT) == S_IFDIR)
 71			return nfserr_isdir;
 72		else
 73			return nfserr_inval;
 74	}
 75	if (type < 0 && (mode & S_IFMT) == -type) {
 76		if (rqstp->rq_vers == 4 && (mode & S_IFMT) == S_IFLNK)
 77			return nfserr_symlink;
 78		else if (type == -S_IFDIR)
 79			return nfserr_isdir;
 80		else
 81			return nfserr_notdir;
 82	}
 83	return 0;
 84}
 85
 86static __be32 nfsd_setuser_and_check_port(struct svc_rqst *rqstp,
 87					  struct svc_export *exp)
 88{
 89	int flags = nfsexp_flags(rqstp, exp);
 90
 91	/* Check if the request originated from a secure port. */
 92	if (!rqstp->rq_secure && !(flags & NFSEXP_INSECURE_PORT)) {
 93		RPC_IFDEBUG(char buf[RPC_MAX_ADDRBUFLEN]);
 94		dprintk(KERN_WARNING
 95		       "nfsd: request from insecure port %s!\n",
 96		       svc_print_addr(rqstp, buf, sizeof(buf)));
 97		return nfserr_perm;
 98	}
 99
100	/* Set user creds for this exportpoint */
101	return nfserrno(nfsd_setuser(rqstp, exp));
102}
103
104static inline __be32 check_pseudo_root(struct svc_rqst *rqstp,
105	struct dentry *dentry, struct svc_export *exp)
106{
107	if (!(exp->ex_flags & NFSEXP_V4ROOT))
108		return nfs_ok;
109	/*
110	 * v2/v3 clients have no need for the V4ROOT export--they use
111	 * the mount protocl instead; also, further V4ROOT checks may be
112	 * in v4-specific code, in which case v2/v3 clients could bypass
113	 * them.
114	 */
115	if (!nfsd_v4client(rqstp))
116		return nfserr_stale;
117	/*
118	 * We're exposing only the directories and symlinks that have to be
119	 * traversed on the way to real exports:
120	 */
121	if (unlikely(!S_ISDIR(dentry->d_inode->i_mode) &&
122		     !S_ISLNK(dentry->d_inode->i_mode)))
123		return nfserr_stale;
124	/*
125	 * A pseudoroot export gives permission to access only one
126	 * single directory; the kernel has to make another upcall
127	 * before granting access to anything else under it:
128	 */
129	if (unlikely(dentry != exp->ex_path.dentry))
130		return nfserr_stale;
131	return nfs_ok;
132}
133
134/*
135 * Use the given filehandle to look up the corresponding export and
136 * dentry.  On success, the results are used to set fh_export and
137 * fh_dentry.
138 */
139static __be32 nfsd_set_fh_dentry(struct svc_rqst *rqstp, struct svc_fh *fhp)
140{
141	struct knfsd_fh	*fh = &fhp->fh_handle;
142	struct fid *fid = NULL, sfid;
143	struct svc_export *exp;
144	struct dentry *dentry;
145	int fileid_type;
146	int data_left = fh->fh_size/4;
147	__be32 error;
148
149	error = nfserr_stale;
150	if (rqstp->rq_vers > 2)
151		error = nfserr_badhandle;
152	if (rqstp->rq_vers == 4 && fh->fh_size == 0)
153		return nfserr_nofilehandle;
154
155	if (fh->fh_version == 1) {
156		int len;
157
158		if (--data_left < 0)
159			return error;
160		if (fh->fh_auth_type != 0)
161			return error;
162		len = key_len(fh->fh_fsid_type) / 4;
163		if (len == 0)
164			return error;
165		if  (fh->fh_fsid_type == FSID_MAJOR_MINOR) {
166			/* deprecated, convert to type 3 */
167			len = key_len(FSID_ENCODE_DEV)/4;
168			fh->fh_fsid_type = FSID_ENCODE_DEV;
169			fh->fh_fsid[0] = new_encode_dev(MKDEV(ntohl(fh->fh_fsid[0]), ntohl(fh->fh_fsid[1])));
170			fh->fh_fsid[1] = fh->fh_fsid[2];
171		}
172		data_left -= len;
173		if (data_left < 0)
174			return error;
175		exp = rqst_exp_find(rqstp, fh->fh_fsid_type, fh->fh_auth);
176		fid = (struct fid *)(fh->fh_auth + len);
177	} else {
178		__u32 tfh[2];
179		dev_t xdev;
180		ino_t xino;
181
182		if (fh->fh_size != NFS_FHSIZE)
183			return error;
184		/* assume old filehandle format */
185		xdev = old_decode_dev(fh->ofh_xdev);
186		xino = u32_to_ino_t(fh->ofh_xino);
187		mk_fsid(FSID_DEV, tfh, xdev, xino, 0, NULL);
188		exp = rqst_exp_find(rqstp, FSID_DEV, tfh);
189	}
190
191	error = nfserr_stale;
192	if (PTR_ERR(exp) == -ENOENT)
193		return error;
194
195	if (IS_ERR(exp))
196		return nfserrno(PTR_ERR(exp));
197
198	if (exp->ex_flags & NFSEXP_NOSUBTREECHECK) {
199		/* Elevate privileges so that the lack of 'r' or 'x'
200		 * permission on some parent directory will
201		 * not stop exportfs_decode_fh from being able
202		 * to reconnect a directory into the dentry cache.
203		 * The same problem can affect "SUBTREECHECK" exports,
204		 * but as nfsd_acceptable depends on correct
205		 * access control settings being in effect, we cannot
206		 * fix that case easily.
207		 */
208		struct cred *new = prepare_creds();
209		if (!new)
210			return nfserrno(-ENOMEM);
211		new->cap_effective =
212			cap_raise_nfsd_set(new->cap_effective,
213					   new->cap_permitted);
214		put_cred(override_creds(new));
215		put_cred(new);
216	} else {
217		error = nfsd_setuser_and_check_port(rqstp, exp);
218		if (error)
219			goto out;
220	}
221
222	/*
223	 * Look up the dentry using the NFS file handle.
224	 */
225	error = nfserr_stale;
226	if (rqstp->rq_vers > 2)
227		error = nfserr_badhandle;
228
229	if (fh->fh_version != 1) {
230		sfid.i32.ino = fh->ofh_ino;
231		sfid.i32.gen = fh->ofh_generation;
232		sfid.i32.parent_ino = fh->ofh_dirino;
233		fid = &sfid;
234		data_left = 3;
235		if (fh->ofh_dirino == 0)
236			fileid_type = FILEID_INO32_GEN;
237		else
238			fileid_type = FILEID_INO32_GEN_PARENT;
239	} else
240		fileid_type = fh->fh_fileid_type;
241
242	if (fileid_type == FILEID_ROOT)
243		dentry = dget(exp->ex_path.dentry);
244	else {
245		dentry = exportfs_decode_fh(exp->ex_path.mnt, fid,
246				data_left, fileid_type,
247				nfsd_acceptable, exp);
248	}
249	if (dentry == NULL)
250		goto out;
251	if (IS_ERR(dentry)) {
252		if (PTR_ERR(dentry) != -EINVAL)
253			error = nfserrno(PTR_ERR(dentry));
254		goto out;
255	}
256
257	if (S_ISDIR(dentry->d_inode->i_mode) &&
258			(dentry->d_flags & DCACHE_DISCONNECTED)) {
259		printk("nfsd: find_fh_dentry returned a DISCONNECTED directory: %s/%s\n",
260				dentry->d_parent->d_name.name, dentry->d_name.name);
261	}
262
263	fhp->fh_dentry = dentry;
264	fhp->fh_export = exp;
265	return 0;
266out:
267	exp_put(exp);
268	return error;
269}
270
271/**
272 * fh_verify - filehandle lookup and access checking
273 * @rqstp: pointer to current rpc request
274 * @fhp: filehandle to be verified
275 * @type: expected type of object pointed to by filehandle
276 * @access: type of access needed to object
277 *
278 * Look up a dentry from the on-the-wire filehandle, check the client's
279 * access to the export, and set the current task's credentials.
280 *
281 * Regardless of success or failure of fh_verify(), fh_put() should be
282 * called on @fhp when the caller is finished with the filehandle.
283 *
284 * fh_verify() may be called multiple times on a given filehandle, for
285 * example, when processing an NFSv4 compound.  The first call will look
286 * up a dentry using the on-the-wire filehandle.  Subsequent calls will
287 * skip the lookup and just perform the other checks and possibly change
288 * the current task's credentials.
289 *
290 * @type specifies the type of object expected using one of the S_IF*
291 * constants defined in include/linux/stat.h.  The caller may use zero
292 * to indicate that it doesn't care, or a negative integer to indicate
293 * that it expects something not of the given type.
294 *
295 * @access is formed from the NFSD_MAY_* constants defined in
296 * include/linux/nfsd/nfsd.h.
297 */
298__be32
299fh_verify(struct svc_rqst *rqstp, struct svc_fh *fhp, int type, int access)
300{
301	struct svc_export *exp;
302	struct dentry	*dentry;
303	__be32		error;
304
305	dprintk("nfsd: fh_verify(%s)\n", SVCFH_fmt(fhp));
306
307	if (!fhp->fh_dentry) {
308		error = nfsd_set_fh_dentry(rqstp, fhp);
309		if (error)
310			goto out;
311	}
312	dentry = fhp->fh_dentry;
313	exp = fhp->fh_export;
314	/*
315	 * We still have to do all these permission checks, even when
316	 * fh_dentry is already set:
317	 * 	- fh_verify may be called multiple times with different
318	 * 	  "access" arguments (e.g. nfsd_proc_create calls
319	 * 	  fh_verify(...,NFSD_MAY_EXEC) first, then later (in
320	 * 	  nfsd_create) calls fh_verify(...,NFSD_MAY_CREATE).
321	 *	- in the NFSv4 case, the filehandle may have been filled
322	 *	  in by fh_compose, and given a dentry, but further
323	 *	  compound operations performed with that filehandle
324	 *	  still need permissions checks.  In the worst case, a
325	 *	  mountpoint crossing may have changed the export
326	 *	  options, and we may now need to use a different uid
327	 *	  (for example, if different id-squashing options are in
328	 *	  effect on the new filesystem).
329	 */
330	error = check_pseudo_root(rqstp, dentry, exp);
331	if (error)
332		goto out;
333
334	error = nfsd_setuser_and_check_port(rqstp, exp);
335	if (error)
336		goto out;
337
338	error = nfsd_mode_check(rqstp, dentry->d_inode->i_mode, type);
339	if (error)
340		goto out;
341
342	/*
343	 * pseudoflavor restrictions are not enforced on NLM,
344	 * which clients virtually always use auth_sys for,
345	 * even while using RPCSEC_GSS for NFS.
346	 */
347	if (access & NFSD_MAY_LOCK || access & NFSD_MAY_BYPASS_GSS)
348		goto skip_pseudoflavor_check;
349	/*
350	 * Clients may expect to be able to use auth_sys during mount,
351	 * even if they use gss for everything else; see section 2.3.2
352	 * of rfc 2623.
353	 */
354	if (access & NFSD_MAY_BYPASS_GSS_ON_ROOT
355			&& exp->ex_path.dentry == dentry)
356		goto skip_pseudoflavor_check;
357
358	error = check_nfsd_access(exp, rqstp);
359	if (error)
360		goto out;
361
362skip_pseudoflavor_check:
363	/* Finally, check access permissions. */
364	error = nfsd_permission(rqstp, exp, dentry, access);
365
366	if (error) {
367		dprintk("fh_verify: %s/%s permission failure, "
368			"acc=%x, error=%d\n",
369			dentry->d_parent->d_name.name,
370			dentry->d_name.name,
371			access, ntohl(error));
372	}
373out:
374	if (error == nfserr_stale)
375		nfsdstats.fh_stale++;
376	return error;
377}
378
379
380/*
381 * Compose a file handle for an NFS reply.
382 *
383 * Note that when first composed, the dentry may not yet have
384 * an inode.  In this case a call to fh_update should be made
385 * before the fh goes out on the wire ...
386 */
387static void _fh_update(struct svc_fh *fhp, struct svc_export *exp,
388		struct dentry *dentry)
389{
390	if (dentry != exp->ex_path.dentry) {
391		struct fid *fid = (struct fid *)
392			(fhp->fh_handle.fh_auth + fhp->fh_handle.fh_size/4 - 1);
393		int maxsize = (fhp->fh_maxsize - fhp->fh_handle.fh_size)/4;
394		int subtreecheck = !(exp->ex_flags & NFSEXP_NOSUBTREECHECK);
395
396		fhp->fh_handle.fh_fileid_type =
397			exportfs_encode_fh(dentry, fid, &maxsize, subtreecheck);
398		fhp->fh_handle.fh_size += maxsize * 4;
399	} else {
400		fhp->fh_handle.fh_fileid_type = FILEID_ROOT;
401	}
402}
403
404/*
405 * for composing old style file handles
406 */
407static inline void _fh_update_old(struct dentry *dentry,
408				  struct svc_export *exp,
409				  struct knfsd_fh *fh)
410{
411	fh->ofh_ino = ino_t_to_u32(dentry->d_inode->i_ino);
412	fh->ofh_generation = dentry->d_inode->i_generation;
413	if (S_ISDIR(dentry->d_inode->i_mode) ||
414	    (exp->ex_flags & NFSEXP_NOSUBTREECHECK))
415		fh->ofh_dirino = 0;
416}
417
418static bool is_root_export(struct svc_export *exp)
419{
420	return exp->ex_path.dentry == exp->ex_path.dentry->d_sb->s_root;
421}
422
423static struct super_block *exp_sb(struct svc_export *exp)
424{
425	return exp->ex_path.dentry->d_inode->i_sb;
426}
427
428static bool fsid_type_ok_for_exp(u8 fsid_type, struct svc_export *exp)
429{
430	switch (fsid_type) {
431	case FSID_DEV:
432		if (!old_valid_dev(exp_sb(exp)->s_dev))
433			return 0;
434		/* FALL THROUGH */
435	case FSID_MAJOR_MINOR:
436	case FSID_ENCODE_DEV:
437		return exp_sb(exp)->s_type->fs_flags & FS_REQUIRES_DEV;
438	case FSID_NUM:
439		return exp->ex_flags & NFSEXP_FSID;
440	case FSID_UUID8:
441	case FSID_UUID16:
442		if (!is_root_export(exp))
443			return 0;
444		/* fall through */
445	case FSID_UUID4_INUM:
446	case FSID_UUID16_INUM:
447		return exp->ex_uuid != NULL;
448	}
449	return 1;
450}
451
452
453static void set_version_and_fsid_type(struct svc_fh *fhp, struct svc_export *exp, struct svc_fh *ref_fh)
454{
455	u8 version;
456	u8 fsid_type;
457retry:
458	version = 1;
459	if (ref_fh && ref_fh->fh_export == exp) {
460		version = ref_fh->fh_handle.fh_version;
461		fsid_type = ref_fh->fh_handle.fh_fsid_type;
462
463		ref_fh = NULL;
464
465		switch (version) {
466		case 0xca:
467			fsid_type = FSID_DEV;
468			break;
469		case 1:
470			break;
471		default:
472			goto retry;
473		}
474
475		/*
476		 * As the fsid -> filesystem mapping was guided by
477		 * user-space, there is no guarantee that the filesystem
478		 * actually supports that fsid type. If it doesn't we
479		 * loop around again without ref_fh set.
480		 */
481		if (!fsid_type_ok_for_exp(fsid_type, exp))
482			goto retry;
483	} else if (exp->ex_flags & NFSEXP_FSID) {
484		fsid_type = FSID_NUM;
485	} else if (exp->ex_uuid) {
486		if (fhp->fh_maxsize >= 64) {
487			if (is_root_export(exp))
488				fsid_type = FSID_UUID16;
489			else
490				fsid_type = FSID_UUID16_INUM;
491		} else {
492			if (is_root_export(exp))
493				fsid_type = FSID_UUID8;
494			else
495				fsid_type = FSID_UUID4_INUM;
496		}
497	} else if (!old_valid_dev(exp_sb(exp)->s_dev))
498		/* for newer device numbers, we must use a newer fsid format */
499		fsid_type = FSID_ENCODE_DEV;
500	else
501		fsid_type = FSID_DEV;
502	fhp->fh_handle.fh_version = version;
503	if (version)
504		fhp->fh_handle.fh_fsid_type = fsid_type;
505}
506
507__be32
508fh_compose(struct svc_fh *fhp, struct svc_export *exp, struct dentry *dentry,
509	   struct svc_fh *ref_fh)
510{
511	/* ref_fh is a reference file handle.
512	 * if it is non-null and for the same filesystem, then we should compose
513	 * a filehandle which is of the same version, where possible.
514	 * Currently, that means that if ref_fh->fh_handle.fh_version == 0xca
515	 * Then create a 32byte filehandle using nfs_fhbase_old
516	 *
517	 */
518
519	struct inode * inode = dentry->d_inode;
520	struct dentry *parent = dentry->d_parent;
521	__u32 *datap;
522	dev_t ex_dev = exp_sb(exp)->s_dev;
523
524	dprintk("nfsd: fh_compose(exp %02x:%02x/%ld %s/%s, ino=%ld)\n",
525		MAJOR(ex_dev), MINOR(ex_dev),
526		(long) exp->ex_path.dentry->d_inode->i_ino,
527		parent->d_name.name, dentry->d_name.name,
528		(inode ? inode->i_ino : 0));
529
530	/* Choose filehandle version and fsid type based on
531	 * the reference filehandle (if it is in the same export)
532	 * or the export options.
533	 */
534	 set_version_and_fsid_type(fhp, exp, ref_fh);
535
536	if (ref_fh == fhp)
537		fh_put(ref_fh);
538
539	if (fhp->fh_locked || fhp->fh_dentry) {
540		printk(KERN_ERR "fh_compose: fh %s/%s not initialized!\n",
541		       parent->d_name.name, dentry->d_name.name);
542	}
543	if (fhp->fh_maxsize < NFS_FHSIZE)
544		printk(KERN_ERR "fh_compose: called with maxsize %d! %s/%s\n",
545		       fhp->fh_maxsize,
546		       parent->d_name.name, dentry->d_name.name);
547
548	fhp->fh_dentry = dget(dentry); /* our internal copy */
549	fhp->fh_export = exp;
550	cache_get(&exp->h);
551
552	if (fhp->fh_handle.fh_version == 0xca) {
553		/* old style filehandle please */
554		memset(&fhp->fh_handle.fh_base, 0, NFS_FHSIZE);
555		fhp->fh_handle.fh_size = NFS_FHSIZE;
556		fhp->fh_handle.ofh_dcookie = 0xfeebbaca;
557		fhp->fh_handle.ofh_dev =  old_encode_dev(ex_dev);
558		fhp->fh_handle.ofh_xdev = fhp->fh_handle.ofh_dev;
559		fhp->fh_handle.ofh_xino =
560			ino_t_to_u32(exp->ex_path.dentry->d_inode->i_ino);
561		fhp->fh_handle.ofh_dirino = ino_t_to_u32(parent_ino(dentry));
562		if (inode)
563			_fh_update_old(dentry, exp, &fhp->fh_handle);
564	} else {
565		int len;
566		fhp->fh_handle.fh_auth_type = 0;
567		datap = fhp->fh_handle.fh_auth+0;
568		mk_fsid(fhp->fh_handle.fh_fsid_type, datap, ex_dev,
569			exp->ex_path.dentry->d_inode->i_ino,
570			exp->ex_fsid, exp->ex_uuid);
571
572		len = key_len(fhp->fh_handle.fh_fsid_type);
573		datap += len/4;
574		fhp->fh_handle.fh_size = 4 + len;
575
576		if (inode)
577			_fh_update(fhp, exp, dentry);
578		if (fhp->fh_handle.fh_fileid_type == 255) {
579			fh_put(fhp);
580			return nfserr_opnotsupp;
581		}
582	}
583
584	return 0;
585}
586
587/*
588 * Update file handle information after changing a dentry.
589 * This is only called by nfsd_create, nfsd_create_v3 and nfsd_proc_create
590 */
591__be32
592fh_update(struct svc_fh *fhp)
593{
594	struct dentry *dentry;
595
596	if (!fhp->fh_dentry)
597		goto out_bad;
598
599	dentry = fhp->fh_dentry;
600	if (!dentry->d_inode)
601		goto out_negative;
602	if (fhp->fh_handle.fh_version != 1) {
603		_fh_update_old(dentry, fhp->fh_export, &fhp->fh_handle);
604	} else {
605		if (fhp->fh_handle.fh_fileid_type != FILEID_ROOT)
606			goto out;
607
608		_fh_update(fhp, fhp->fh_export, dentry);
609		if (fhp->fh_handle.fh_fileid_type == 255)
610			return nfserr_opnotsupp;
611	}
612out:
613	return 0;
614
615out_bad:
616	printk(KERN_ERR "fh_update: fh not verified!\n");
617	goto out;
618out_negative:
619	printk(KERN_ERR "fh_update: %s/%s still negative!\n",
620		dentry->d_parent->d_name.name, dentry->d_name.name);
621	goto out;
622}
623
624/*
625 * Release a file handle.
626 */
627void
628fh_put(struct svc_fh *fhp)
629{
630	struct dentry * dentry = fhp->fh_dentry;
631	struct svc_export * exp = fhp->fh_export;
632	if (dentry) {
633		fh_unlock(fhp);
634		fhp->fh_dentry = NULL;
635		dput(dentry);
636#ifdef CONFIG_NFSD_V3
637		fhp->fh_pre_saved = 0;
638		fhp->fh_post_saved = 0;
639#endif
640	}
641	if (exp) {
642		cache_put(&exp->h, &svc_export_cache);
643		fhp->fh_export = NULL;
644	}
645	return;
646}
647
648/*
649 * Shorthand for dprintk()'s
650 */
651char * SVCFH_fmt(struct svc_fh *fhp)
652{
653	struct knfsd_fh *fh = &fhp->fh_handle;
654
655	static char buf[80];
656	sprintf(buf, "%d: %08x %08x %08x %08x %08x %08x",
657		fh->fh_size,
658		fh->fh_base.fh_pad[0],
659		fh->fh_base.fh_pad[1],
660		fh->fh_base.fh_pad[2],
661		fh->fh_base.fh_pad[3],
662		fh->fh_base.fh_pad[4],
663		fh->fh_base.fh_pad[5]);
664	return buf;
665}
666
667enum fsid_source fsid_source(struct svc_fh *fhp)
668{
669	if (fhp->fh_handle.fh_version != 1)
670		return FSIDSOURCE_DEV;
671	switch(fhp->fh_handle.fh_fsid_type) {
672	case FSID_DEV:
673	case FSID_ENCODE_DEV:
674	case FSID_MAJOR_MINOR:
675		if (exp_sb(fhp->fh_export)->s_type->fs_flags & FS_REQUIRES_DEV)
676			return FSIDSOURCE_DEV;
677		break;
678	case FSID_NUM:
679		if (fhp->fh_export->ex_flags & NFSEXP_FSID)
680			return FSIDSOURCE_FSID;
681		break;
682	default:
683		break;
684	}
685	/* either a UUID type filehandle, or the filehandle doesn't
686	 * match the export.
687	 */
688	if (fhp->fh_export->ex_flags & NFSEXP_FSID)
689		return FSIDSOURCE_FSID;
690	if (fhp->fh_export->ex_uuid)
691		return FSIDSOURCE_UUID;
692	return FSIDSOURCE_DEV;
693}